MODIS/TERRA MOD13A3 Vegetation Indices Monthly L3 Global 1km

Global MODIS vegetation indices are designed to provide consistent spatial and temporal comparisons of vegetation conditions. Blue, red, and near-infrared reflectance, centered at 469-nanometers, 645-nanometers, and 858-nanometers, respectively, are used to determine the MODIS daily vegetation indices.
The MODIS Normalized Difference Vegetation Index (NDVI) complements NOAA's Advanced Very High Resolution Radiometer (AVHRR) NDVI products provide continuity for time series historical applications. MODIS also includes a new Enhanced Vegetation Index (EVI) that minimizes canopy background variations and maintains sensitivity over dense vegetation conditions.
The EVI also uses the blue band to remove residual atmosphere contamination caused by smoke and sub-pixel thin cloud clouds. The MODIS NDVI and EVI products are computed from atmospherically corrected bi-directional surface reflectance that have been masked for water, clouds, heavy aerosols, and cloud shadows. https://lpdaac.usgs.gov/lpdaac/products/modis_products_table

全球中分辨率成像光谱仪（MODIS）植被指数旨在实现植被状况的一致性空间与时间对比分析。研究采用分别以469纳米、645纳米及858纳米为中心波长的蓝光、红光与近红外反射率，计算得到MODIS每日植被指数。
中分辨率成像光谱仪归一化差分植被指数（NDVI）可与美国国家海洋和大气管理局（NOAA）甚高分辨率辐射计（AVHRR）的NDVI产品形成互补，为历史时序类应用提供数据连续性保障。MODIS还新增了增强型植被指数（EVI），该指数可最大限度抑制冠层背景噪声变化，并在高密度植被区域仍能保持观测灵敏度。
增强型植被指数（EVI）还会利用蓝光波段，去除由烟雾及亚像元级薄云引发的大气残留污染。MODIS NDVI与EVI产品均基于经过大气校正的双向地表反射率计算得到，且已对水体、云层、重度气溶胶及云影进行掩膜处理。https://lpdaac.usgs.gov/lpdaac/products/modis_products_table